802
FXUS63 KDVN 031121
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
621 AM CDT SUN MAY 3 2026
KEY MESSAGES
- THERE WILL BE A PERIOD OF 3-4 HOURS FROM MID-MORNING THROUGH
EARLY AFTERNOON OF WINDS GUSTING UP TO 40 MPH AHEAD OF THE
COLD FRONT.
- THE STORM PREDICTION CENTER HAS A MARGINAL (LEVEL 1 OUT OF 5)
RISK OF SEVERE STORMS MONDAY AFTERNOON/EVENING FOR THE ENTIRE
AREA. DAMAGING WINDS AND HAIL ARE THE PRIMARY RISKS.
- AN OMEGA BLOCK ON THE WEST COAST WILL KEEP COOLER THAN NORMAL
TEMPERATURES ACROSS THE AREA TUESDAY THROUGH FRIDAY WITH
ANOTHER WARM-UP FOR THE WEEKEND.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 158 AM CDT SUN MAY 3 2026
UPPER LEVEL DISTURBANCE AHEAD OF A COLD FRONT WILL SWEEP THROUGH THE
AREA THROUGH MID-DAY WITH ISOLATED TO SCATTERED SHOWERS.
THERE HAS BEEN A FAIRLY PERSISTENT SIGNAL FROM THE HRRR SHOWING A
PERIOD OF 3-4 HOURS IMMEDIATELY BEHIND THE RAIN SHOWERS AND AHEAD OF
THE COLD FRONT OF WINDY CONDITIONS. THE LATEST ITERATION OF THE HRRR
CONTINUES THIS SIGNAL BUT NOT AS STRONG AS PREVIOUS RUNS. IT DOES,
HOWEVER, APPEAR THERE WILL BE A PERIOD OF WIND GUSTS OF UP TO 40 MPH
THIS MORNING WEST OF THE MISSISSIPPI. EAST OF THE MISSISSIPPI THE
WIND GUSTS ARRIVE LATE MORNING INTO EARLY AFTERNOON BUT ONLY GUSTING
UP TO 30-35 MPH.
RIGHT NOW THERE ARE NO PLANS FOR ANY WIND HEADLINES. OBSERVATION
TRENDS THROUGH SUNRISE WILL BE WATCHED CLOSELY FOR ANY POSSIBLE
CHANGES.
EARLY THIS EVENING WINDS WILL QUICKLY DROP TO UNDER 10 MPH AS HIGH
PRESSURE QUICKLY MOVES THROUGH THE MIDWEST. ATTENTION THEN TURNS TO
MONDAY.
LONG TERM /MONDAY THROUGH SATURDAY/
ISSUED AT 158 AM CDT SUN MAY 3 2026
MONDAY/MONDAY NIGHT
ASSESSMENT...A CERTAINTY (>95%) OF WARMER THAN NORMAL TEMPERATURES.
LOW TO MEDIUM (25-50%) CONFIDENCE ON AFTERNOON STORMS.
AFTER A DRY MONDAY MORNING, ALL MODELS PUSH A STRONG COLD FRONT
THROUGH THE AREA DURING THE AFTERNOON/EVENING. HOWEVER, THERE ARE
TIMING DIFFERENCES BETWEEN THE MODELS. ADDITIONALLY, ALTHOUGH MID-
LEVEL LAPSE RATES WILL BE QUITE STEEP, MOISTURE AVAILABILITY IS
SOMEWHAT LIMITED FOR STORM DEVELOPMENT.
FROM THE LARGE SCALE, MOISTURE HAS TO WORK ITS WAY AROUND HIGH
PRESSURE OVER THE GULF. THE LONGER TRIP WITH THE MOISTURE RAISES
QUESTIONS AS TO HOW MUCH MOISTURE WILL BE AVAILABLE FOR DIURNAL
CONVECTION.
THE MOST LIKELY SCENARIO IS FOR DIURNAL CONVECTION TO DEVELOP RIGHT
ALONG THE COLD FRONT DURING PEAK HEATING MONDAY AFTERNOON. GIVEN THE
TIMING DIFFERENCES WITH THE COLD FRONT, THE MODEL CONSENSUS IS
INDICATING A MORE ISOLATED (20%) COVERAGE OF CONVECTION FOR MUCH OF
THE AREA. THE EXCEPTION IS THE LOW END SCATTERED (25-30%) COVERAGE
NORTH OF HIGHWAY 30.
STORM COVERAGE MAY INCREASE MONDAY EVENING AS A WEAK LOW MOVES EAST
NORTHEAST FROM KANSAS INTO CENTRAL ILLINOIS. THIS IS REFLECTED IN
THE 30-70% RAIN CHANCES MONDAY EVENING FROM THE MODEL CONSENSUS WITH
THE HIGHEST POPS FROM NORTHEAST MISSOURI TOWARD CHICAGO.
INTERESTINGLY, NBM 3 HR THUNDERSTORM PROBABILITIES NEVER GET ANY
HIGHER THAN 25-30% MONDAY EVENING SUGGESTING MUCH LOWER COVERAGE
THAN THE MODEL CONSENSUS.
THE DETERMINISTIC ECMWF IS EVEN DRIER SUGGESTING ONLY 10-20%
COVERAGE MONDAY EVENING.
THE STORM PREDICTION CENTER NOW HAS A MARGINAL (LEVEL 1 OUT OF 5)
RISK FOR SEVERE STORMS MONDAY AFTERNOON/EVENING. AGAIN, MOISTURE IS
LIMITED BUT IF STORMS DO DEVELOP, THE STEEP MID-LEVEL LAPSE RATES
WOULD ALLOW THE STRONGER STORMS TO PRODUCE 1 INCH HAIL AND 60 MPH
WINDS, ESPECIALLY WITH THE STRONGER FORCING FROM THE APPROACHING
SURFACE LOW.
SHOWERS AND SOME STORMS WILL PERSIST LATE INTO MONDAY NIGHT AS THE
WEAK LOW SLOWLY MOVES THROUGH THE AREA. THE 'RELATIVELY' BETTER RAIN
CHANCES WILL BE SOUTH OF I-80.
TUESDAY THROUGH SATURDAY
ASSESSMENT...VERY HIGH (>85%) CONFIDENCE OF COOLER THAN NORMAL
TEMPERATURES
GIVEN THE TIMING DIFFERENCES BETWEEN THE VARIOUS MODELS, THE MODEL
CONSENSUS HAS RAIN PERSISTING INTO TUESDAY BEHIND THE FRONT. THE
RAIN WILL SLOWLY END FROM NORTHWEST TO SOUTHEAST DURING THE
AFTERNOON WITH TUESDAY NIGHT BEING DRY.
THE LARGE OMEGA BLOCK ON THE WEST COAST WILL KEEP NORTHWEST FLOW AND
COOL CANADIAN AIR ACROSS THE MIDWEST FOR THE REMAINDER OF THE WORK
WEEK WITH A WARM-UP FOR THE WEEKEND. ALL MODELS SHOW WEAK
DISTURBANCES IN THE FLOW ALOFT MOVING THROUGH THE AREA ON A NEAR
DAILY BASIS WHICH WOULD BE CAPABLE OF PRODUCING RAIN SHOWERS IF
SUFFICIENT MOISTURE IS PRESENT.
THERE ARE TWO DISTURBANCES OF NOTE THAT HAVE THE POTENTIAL TO BRING
DIURNAL SHOWERS; THURSDAY AND FRIDAY. A COLD POCKET OF AIR ALOFT ON
THURSDAY WILL PRODUCE VERY STEEP MID-LEVEL LAPSE RATES, WHICH WITH
DAYTIME HEATING, SHOULD BE MORE THAN ENOUGH TO POP ISOLATED TO
SCATTERED (20-30%) SHOWERS THURSDAY AFTERNOON. ON FRIDAY, THE COLD
POCKET ALOFT HAS MOVED OFF TO THE EAST SO THE MID-LEVEL LAPSE RATES
ARE NOT NEARLY AS STEEP. THUS ANY DIURNAL SHOWERS WOULD BE MORE
ISOLATED AT 10-20% COVERAGE.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 615 AM CDT SUN MAY 3 2026
ISOLATED TO SCATTERED SHRA WILL END ACROSS EASTERN IOWA AND MOST
OF NORTHERN ILLINOIS BY 18Z/03. OBSERVATION TRENDS ACROSS
CENTRAL IOWA SHOW GUSTS 20-25 KNOTS WITH ISOLATED PEAK GUSTS OF
30 KNOTS. THUS EARLIER THINKING OF A 3-4 HOUR WINDOW BEHIND THE
SHRA OF GUSTS UP TO 35 KNOTS STILL LOOKS REASONABLE. STARTING
AROUND 00Z/04 WIND SPEEDS WILL DROP TO 10 KNOTS OR LESS AS HIGH
PRESSURE ARRIVES. GUIDANCE SUGGESTS WINDS WILL BACK AND BECOME
SOUTHWEST AFTER 06Z/04.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...08
LONG TERM...08
AVIATION...08
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